Isobutane Catalytic Dehydrogenation to Isobutylene on VO_x/SiO_2 Catalysts

Isobutane catalytic dehydrogenation to isobutylene on VOx/SiO2 catalysts prepared by impregnation method was studied in a micro-fixed bed reactor under various conditions.The surface composition of catalysts was characterized by XRD and Raman techniques.The effects of V2O5 loading,reaction temperature and molar ratio of hydrogen to isobutane on the dehydrogenation of isobutane to isobutylene was investigated.The results showed that when the V2O5 loading exceeding 9%,the catalysts surface started to form crystal V2O5,and the activity situ reduced owing to the pore jammed by crystal.The 9%V2O5 loading was the best loading.When reaction temperature was between 590~620 ℃,ratio of H2 to n-C4H10 was between 1~3,the catalystic activity was highest.The paper also pointed out the C1~C3 cracking was influenced mainly by reaction temperature,hardly by the conditions of ratio of H2 to n-C4H10 and V2O5 loadings.